Method of making toothbrush handles



Jan 5, 1932.

F. A. PARKHURST METHOD OF MAKING TOOTHBRUSH HANDLES Filed Aug. 2, 1929 Izzy/222101":

' the fins and finishing the Patented Jan. 5, 1932 STATES FREDERIG A. PARKHURST,

OF BETHESDA, MARYLAND, ASSIGNOR, BY MESNEASSIGN- MENTS, T0 PRO-PHY-LAC-TIC' BRUSH COMPANY, OF WILMINGTON, DELAWARE, .:A j

CORPORATION OF DELAVTARE METHOD OF MAKING TOOTHBBUSH HANDLES Application filed August 2, 1929. SefialNo. $83-$74.

This invention relates to a method of making tooth brush handles and the general object of the invention is to reduce the expense of making such handles.

Heretofore it has been the general practice to make tooth brush handles by cutting rectangular blanks in predetermined size and shape from a sheet of material, molding the blank in a die press to form a handle of proper size and shape and then finishing and polishing the handle manually. In this method the rectangular blank was of necessity larger than the finished handle and the excess material was forced out between the edges of the die forming a fin or flash. These fins or flashes were around the outside edges of the handles and had to be removed by hand methods as it was not practical to do the work by machine. The method described involved a large number of steps and was slow and caused waste because of the loss of material contained in the large fins or flashes amounting to from 10 to 15 per cent and also because of the expense of removing blank.

The object of my invention, therefore, is to provide an economical and practical method of making tooth brush handles which will avoid the difliculties and causes of expense already mentioned.

I accomplish this result by molding a large number of tooth brush handles in gangs or groups, the handles being on edge so that the fin or flash which connects each handle with the next handle in the group is connected to the middle of the back or front face i. e. the large face of the blank and not to the edge. In practicing my method and after the molding of each group of handles is completed the handles .are readily separated from each other by the fingers, by reason of the fact that the fin or flash connecting them is very small and exceedingly thin, thus permitted of readily bufling or otherwise removing what remains of the fin or flash from the two flat faces of each blank.

This can be done cheaply and economically by passing the blanks through suitable automatic bufling machines.

Other objects i of the invention will appear from the following description and appended claims when taken in connection with the accompanying drawings, in which 'Fig. *1 is a perspective view-ofa blank of pyrox-ylin or similar material.

2 is aperspecti-ve View ofa :gang die with a gang of molded handles therein.

Fig. 3 FlS a perspective view of the molded gang of handles.

Fig. 4 is a section through several of the handles, illustrating one method of separating the handles.

Fig. 5 is a perspective view of .a separated handle showing the fin 'or :flash on one face th'ereofjthe flash being 'ofeiraggerated thickness.

Fig. 6 is fa handle. I

Before explaining in detail the present invention, it is'to b'e'un'derstood that the'invention is not limited in its application to the 'c'l'etails of construction and arrangement'of partsillustrated in the accompanying draw- :ings,-since the invention is capable'of other embodiments and of being practised or carried out in various ways. Also ritis to be understOod-thaftIthe phraseology orterminology perspective view of a finished employed herein is for the purpose of ='de- I scription and not of limitation,:andit is not intended to 'limit the invention beyond the terms of theseveral claims hereto appended as considered in view of the priorart and the requirements thereof.

In accordance with my method, I'employ, preferably, a sheet or slab of either partly seasoned or fully seasoned pyroxyli'n materia'h suchas the slab 10, Fig. 1. The slab may be warmed on a steam table or elsewhere and placed in the slab forming die which comprises upper and lower die members :11 and 112 respectively and is provided with a series of mold cavities corresponding in shape to Ithe handles to be formed, these :being arranged with their flat faces toward each other. The die is so constructed that the flash or fin i. e. the portion of waste stock is exceedingly thin. In practice this is hardly thicker than tissue paper, but suflicient to hold the blanks together in a gang or cake.

The die is put into an hydraulic press and the slab therein is formed into a group or gang of molded tooth brush handles, as shown at 13 in Fig. 3. It will be seen from Figs. 3, 4: and 5 that the handles are positioned on edge and that they are interconnected by, webs 14 called flash. The next operation is to separate the individual handles of the group 13, which is done, preferably, by a slight pressure of the fingers. After separation of the handles by the fingers, it will be seen that each handle is provided on opposite flat faces with an exceedingly thin fin or flash 16. By having the fins or flashes on 15 opposite flat faces of the handle rather than surrounding the edges of the handle, the fin or flash can be removed by a mechanical ashing or buifing device, after which a mechanical polisher may be employed to give the handle a highly polished finish. This can be done only with difficulty if at all where the flash is on the edge of the blank. Then if desired the handles may be carried through a lacquer dip and humid drying chamber, or the handles may be spread automatically on a foraminous work support and sprayed with lacquer. The finished handle is shown in Fig. 6. v

I claim:

3 1. The hereindescribed method of making tooth brush handles which consists in molding a blank of pyroxylin material in a gang die to provide a gang or group of handles on edge with a fin connecting the middle of the adjacent faces of adiacent handles, separating the individual handles, and thereafter removing the fins.

2. The hereindescribed method of making tooth brush handles in gangs or groups, which consists in molding a slab of pyroXylin to form a group of handles on edge connected by fins at the middle of the adiacent faces, separating the individual handles, and removing the fins. 3. The method of making tooth brush handles which consists in molding a plurality of blanks in a die, said blanks being connected by a thin flash or fin joining the blank on the flat sides of the blank, and then separating the blanks and removing the-flash.

4. The method of making tooth brush handles which consists in molding a plurality of blanks in a die, said blanks being connected by a flash or fin joining the flat sides of proximate blanks, said fin being thin enough to permit the blanks to be readily broken apart without injury, separating the blanks and removing the traces of the flash.

In testimony whereof I affix my signature.

FREDERIC A. PARKI-IURST. 

